I am not sure what to do next, and I need some help.
I replaced the rectifiter tube to get the voltages up.
I double checked the wiring of my new electrolytic capacitors (C101 and C102) and they are correct.
I replaced R202. That gave me a whine in the audio that is removed with the volume control.
Now my C101 and C102 have blown. Smoke everywhere. I have two new caps on hand but do not want to replace them until I can figure out why they blew. Voltage rating on the blown caps were 500 volts.
I'm thinking I may have a short somewhere, and if so, how do I track that down.
Thanks, Terry
See if your rectifier tube is shorted or very leaky.
Shorts do not make capacitors blow.
Although it is always a good idea to check for them.
Recheck the polarity of C101 and C102.
Steve
That too of course.
Did you re-stuff the caps? Or did you use new bare caps? If you re-stuffed, are you sure you did connect + to + and - to - when sealing the cans?
When you say new capacitors, what exactly does that mean?
I bought new 16 mf axial capacitors from Justradios. As for polarity, I am pretty sure that I installed them correctly.
I will get back to the project next week when an Electrical Engineer friend can help me and verify the work.
Thanks for the help.
16 mF or uF? That makes about 1000 times the difference. You talking microfarads, right?
Axials have the "-" going to the case and the "+" insulated, as usual, plus there are usually "+" side markings.
If you are sure and you did not re-stuff anything that would be another variable.....I would
1) check my rectifier tube
2) with the rectifier out, put a meter and measure the transformer output to the rectifier. What if it is doubled? Not sure how that could happen, but.....
I am still (if you are sure of polarity) leaning towards a bad rectifier.
Actually, in this country, MFD = mf = mF = uF.
We used to call pF "mmfd" or "mmf" but we've standardized on "pF" these days.
We did not use the in between nanofarad or "nF" in the USA.
Ron, have to disagree.
I cannot speak for the ham or antique radio community lingo, and the marking on the old capacitors was different from today (then again those were condensers, not caps
) ), but in today's EE practice in the US:
uF - microfarad
mF - not used. 1000uF is what it is.
nF - nanofarad.
pF - picofarad.
In general, in engineering and physics, today:
m - always ""milli", 1/1000
u - always ""micro, 1/1000,000, from its resemblance to Greek "mu" which starts the word "Mikro".
n - always "nano", 1/1,000,000,000
I was speaking from the antique radio collecting perspective, and had no knowledge of which terms modern engineers use.
That I have no argument with.
Just kinda hard to switch between the two systems. When it is imperial and metric - easy, they have nothing in common, no confusion there. (although Martial modules occasionally crash)
Or between Russian and English.
But the same system where while speaking to some folks "mF" is a microfarad and to some others - 1000 microfarads, this gets downright confusing.